Air Purifier

Finding the right air purifier can be difficult and confusing. There are hundreds of different models, and most manufacturers claim that their air purifier offers a new, unique and revolutionary technology, most of which is just marketing.

There are, however, some air purifiers that achieve fantastic results. These are endorsed by opinion leaders, and used in leading hospitals, research facilities & government buildings around the world.

What is an air purifier?

An air purifier is a device that removes particulate and/or gaseous pollution from the air. They range widely in size and design, from large installations used on an industrial scale to small portable machines that could be used in a bedroom. Residential air purifiers can either stand-alone or be used to clean the air in the whole house. There has always been a perceived need to clean the air we breathe. For example, Leonardo Da Vinci had the notion that finely woven cloth dipped in water would protect the military from toxic powders. At the end of the 18th century, the German explorer and naturalist Alexander von Humboldt devised a primitive respirator for use in mining, while Lewis P. Haslett’s ‘lung protector’, which received its patent in 1848, used moistened wool with a one way valve to filter dust out of the air. The United States Army Chemical Corps and the United States Atomic Energy Commission developed the High Efficiency Particulate Air (HEPA) filter system. The filter was devised to protect against the spread of radioactive dust during the Manhattan Project, during the development of the Atom bomb. The first HEPA filters were rigid and unwieldy machines, rather contrastingly to their modern counterparts.

What types of air purifier are there, and how do they work?

There are many air purifying systems and models available, which fall into four basic categories, described below:

HEPA Air PurifiersThe US Environmental Protection Agency recommends High Efficiency Particulate Air filters as the most effective of the mechanical air purifiers. The filter media in a HEPA air purifier is a specialised filter consisting of a folded mat of fibres. It has three different modes of action, each of which acts upon a different size of particle. Interception deals with particles above 0.4 microns in diameter and involves the particle sticking to a fibre in the filter when it comes close to it. During impaction, the particle is blown towards the fibres by the airstream on which it is traveling, collides with them and sticks to the mat. Then there is diffusion, which mainly affects smaller particles, of a diameter below 0.1 microns. The particle collides with air molecules, which throw it off course. Diffusion keeps the particle within the filter until it is captured by impaction or interception. What about particles between these size ranges? They are captured, but with a very small decrease in efficiency.

It is a little known fact that an air purifier, such as the IQAir HealthPro 250, can take up to 99.95% of particle pollution out of the air. The movement of particles at 0.3 microns is erratic in nature, making it difficult for the air purifier to capture it. There is no other domestic air purifier that comes close to this kind of filtration efficiency. Click here to learn more about HEPA filtration.

Electronic Air PurifiersElectronic air purifiers work by giving particles that pass through the unit an electric charge, and then uses electrostatic attraction to trap the particles. There are different kinds of electronic air purifiers; two popular versions are electrostatic precipitators and ionisers. The electrostatic precipitator sucks air into the unit, charges up the air particles in the first section, and then passes the air particles to a pair of plates bearing an opposite charge, thereby sticking the particles onto the plates. An ioniser acts externally rather than internally in that it releases ions into the environment. This charges up the particles in the air and they become attracted to their surroundings by electrostatic attraction. It is very similar to rubbing a balloon against your jumper and making it stick to the wall. The problem here is that electrically charged pollution can be an inconvenience when it sticks to walls, furnishings and other objects in your house. For that reason we do not recommend air purifiers that use ionisation alone and do not combine it with a HEPA-like filter.

The efficiency with which an air purifier collects the air should be as high as possible. A common problem with ionising air purifiers, is that any air pollution that is not captured by the air purifier, but is electrically charged will be released back into the room and will attach itself to something else within your home. So if the air cleaners collection efficiency is only 80%, then you are releasing 20% of charged air pollution particles into your environment.

Another problem with air purifiers that use ionisation is that their filtration efficiency tends to become less effective with use. Many ionisers might start out with a particle collection efficiency of 90% or even 99%, but that efficiency can often drop quickly to as low as 50% or less. The reason that the collection efficiency decreases, is that if enough dust is accumulated on the air cleaner’s collection surface, then that dust functions as insulation. The charge will not pass through the layer of dust, letting the particle pass through the collection surface without being captured.

To ensure that your ioniser is working most efficiently, you should make sure that its filters are replaced regularly.

UV Air PurifierUltra-Violet (UV) light is a very short wavelength of radiation, which kills microorganisms, such as viruses, bacteria and moulds if they are exposed to the light for a significant amount of time. The performance of UV light killing microorganisms depends upon the dose of UV light air pollution is exposed to, the length of time the microorganisms are exposed to the light, and the nature of the microorganism involved. Not all bacteria and mould spores can be killed by UV light. In general, microorganisms have to be exposed to UV light for several hours to be killed. Given that the air passes through an air purifier within a fraction of a second, UV light is not an effective way to eliminate microorganisms from the air.

Gas / Chemical Air PurifierWhat if you’re concerned about Volatile Organic Compounds (VOCs) rather than house dust mite allergens or other particles? VOCs are gaseous molecules, rather than particles. Unfortunately, none of the air purifier technologies discussed above, working by themselves, will remove them. Only air purifiers containing activated granular carbon, or equivalent filters can remove VOCs. What is important here is the quality of the carbon that is being used. Carbon dust, which is relatively cheap, will not be very effective. Some air purifiers, like the IQAir HealthPro 250, combine a HEPA filter with a powerful gas filter, thereby removing the widest range of pollutants. Alternatively, you might want to consider an IQAir GC VOC or IQAir GC MultiGas for environments with elevated chemical contamination.

Which air purifiers will remove particle pollution?

The HEPA and electrostatic air purifiers remove particle pollution. The filtration efficiency of the HEPA air purifier, however, will be much more consistent than that of the electrostatic air purifier.

Which will remove smoke and chemical pollution?

An air purifier fitted with high quality activated carbon filters will remove smoke and chemical gaseous pollution. For instance, the IQAir HealthPro 250 contains both a HEPA filter (a HyperHEPA filter which filters out particles down to 0.003 microns) and an activated carbon and impregnated alumina filter to remove a wide range of gases and odours.

What is an air washing air purifier?

Air washing air purifiers can be effective for removing larger particle pollution from the air. A problem, however, tends to arise whenever one combines water and bacteria from dirty air, which naturally results in growing more contamination. To avoid hygiene issues such as mould growing in your air cleaner, it is advisable to use chemicals to fight bacterial growth. It is important to keep in mind, however, that some of these chemicals will be released into the air when the water in the air washer air purifier evaporates. Inhaling these chemicals can result in severe reactions in people with respiratory conditions.

What are ozone air purifiers?

Ozone can clean the air by affecting the cells that are exposed to it. This makes ozone very effective in cleaning bacteria and mould infestations in hard to reach places. Ozone, however, does not discriminate one cell against another. It will affect a person’s lungs in the same way that it attacks unwanted bacteria. For this reason, ozone has absolutely no place in everyday air purification in a domestic setting. Ozone should only be used to clean the air if no humans or animals are around. Some ionising air purifiers are producing small amounts of ozone. The ionising process breaks down oxygen molecules in the air, producing ozone in the process. Some ionising air cleaners have been banned for these reasons.

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Air Purifier Information | Air Purifier Expert Advice & FAQs Articles

The Chinese air purifier standard has faced frequent changes in the last 15 years. At times it has not been very specific in telling companies what they can and can’t say about their air purification systems. It wasn’t until 2008 that the government decided that change was necessary; they then updated the 2002 Chinese air purifier standard to attempt to improve the quality of air purification systems. Despite this, there has been many attempts to exaggerate on air purifier claims in China alone.

OIT air purifiers have been widely used in South Korea and this had led to major recalls, the reason being that OIT is a chemical that has been widely categorised as unsafe. You might expect an air purifier to improve your health, certainly not to damage it by emitting toxic chemicals; however, recently a local broadcast in South Korea noted that tests by the Environment Ministry showed that emissions of a potentially harmful substance, OIT, had been detected in no less than 51 air purifiers!

Studies have shown how clean air - free from particulate pollution such as traffic pollution, mould, dust, viruses, bacteria as well as chemicals and gases - help with shallow breathing, improves quality of sleep and can prevent a wide range of short term and long-term health problems...

Air purification technologies have made many advances since the first HEPA (High Efficiency Particulate Air) filters were developed as a tool in nuclear technology in the 1940s. There are now many different types of air purification technologies that are being used today and, although the range on offer may seem confusing at first, this means that with a little sound research you should find an air purifier to meet your needs – whether to ease the symptoms of Multiple Chemical Sensitivity or Sick Building Syndrome, or to protect a child with allergies or asthma.

Have you ever wondered how quickly the IQAir HealthPro air purifiers clear a room filled with toxic smoke?
Then check out this video of IQAir's President Frank Hammes stepping into a smoke chamber with only an IQAir HealthPro to protect him.

There are so many different kinds of air purifiers and air cleaners on the market, that it’s hard to know where to start if you want to buy an air purifier for your home. Let’s start by asking: How does an Air Purifier Work, and how they can help you? In other words, what’s in the box, and what will it do?

A HEPA air purifier is a powerful weapon in your fight against mould because it will effectively capture mould spores in the air. But it is also important to tackle the main cause of mould, which is damp conditions and, if mould has built up, to remove it - either with a bleach-based cleaner, a non toxic anit-allergen spray such as ADS from Allersearch, or if it is really bad, with professional help.
Mould is the name given to small, multi-celled fungi. Mushrooms are also fungi, as are yeasts, which are single-celled fungi.

What can you expect from an air purifier? That of course depends which brand and model of air purifier you buy. We do not recommend buying an reverse engineered air purifier - even if the manufacturer has a household name and produces excellent other products, such as TVs, cars or even duct tape.

A Parent Tested Parent Approved air purifier has been chosen as one of the companies exclusive “Top 10 Products for Parent.” The air purifier chosen by Parent Tested Parent Approved is the IQAir’s HealthPro air cleaner.